Apparatus for making honeycomb cores for sandwich-type structures



Feb. 23, 1954 G. A. UNGAR 2,670,026

APPARATUS FOR MAKING HONEYCOMB CORES FOR SANDWICH-TYPE STRUCTURES Original Filed March 18, 1948 4 Sheets-Sheet 1 UN Mum ar IRMA u/va/m, Azw/Al/smnrmx Feb 23, 1954 G. A. UNGAR 2670026 APPARATUS FOR MAKING HONEYCOMB CORES FOR SANDWICH-TYPE STRUCTURES Ongmal Filed March 18, 1948 Y 4 Sheets-Sheet 2 u WT MM.

mlw ww m D \A NN I I I I Mil H H 11 i Q lnve n? o r- GUS-FAVE A. UNGAR,DECEASL, A By \RMA UNsAmAowms-rRA-rmx Feb. 23, 1954 G. A. UNGAR 2,670,026

APPARATUS FOR MAKING HONEYCOMB CORES FOR SANDWICH-TYPE STRUCTURES Original Filed March 18, 1948 4 Sheets-Sheet 3 I" ,inve rfl'or Gus-rAvE A-UNGAR.

DECEASED 5y \RMA UNGAR.

Aummls-rnATmx' BY 4 V Anne/v5 Feb. 23, 1954 A. UNGAR APPARATUS FO MAKING HONEYCOMB CORES FOR SANDWICH-TYPE STRUCTURES Original Filed March 18, 1948 4 Sheets-Sheet 4 R J M N G w M A V U e M T a A A 5mm 7 I; A w m T A m s u fi W E G D Patented Feb. 23, 1954 APPARATUS FOR MAKING HONEYCOMB CORES FOR SANDWICH-TYPE STRUC- TUBES Gustave A. Ungar, deceased,late of New Rochelle, N. 31., by Irma Ungar, administratrix, New Rochelle, N. Y., assignor to Douglas Aircraft Company, Inc., Santa Monica, Calif.

Original application March 18,1948, Serial No.

15,708. Divided and this application February 1,1952, Serial No. 269,548

The present.- invention relates: to an apparatus for-producing multi-cellular webs such as honeycomb filler or core for sandwich-type panels which are of light weight and yet capable of supporting substantial loads, as when utilized as structural elements. Such panels consist of a top and bottom layer of metallic or nonmetallic sheet material, such as thin sheet metal, plywood, plastic sheeting, or plastic-impregnated cardboard.

and the like, which layers encompass between them a honeycomb filler or core. Such filler or core may consist of avariety of materials which provides suflicient transverse strength in the structure in which they separate-the end plates to which the filler or core is suitably attached.

The general object of the invention is to provide animproved apparatus for the manufacture of such a filler or core in a continuous operation from a single sheet of material, such as paper or fabric, impregnated with any suitable plastic reinforcing agent. This application is a division of. the copending application, Serial No. 15,708, filed March 18,1948.

In the art of making honeycomb cores the usual practice has heretofore been as follows: A number of sheets, say, of paper or fabric, are striped in long parallel lines with adhesive on one or both sides, and a pile of such sheets is pressed toset' the adhesive, thus resulting in a laminated pile of sheets each two adhering at the area of the striping. The honeycomb is: made by cutting the stacks of sheets into the desired Width, and then expanding or drawing the laminated pile as far apart as practicable, so that the nonadhering areas'of the adjacent sheets bend with respect to the adhering areas thus forming a plurality of hexagonal cells. It is understood of course that the material, such as paper or fabric, is preferably impregnated with a suitahle stiffening plastic or the. like so' that the formed honeycomb will retain its shape after expansion. lifterv the cellular structure. is obtained it is usually heated for the purpose of curing the impregnant, such structure then becoming permanent as to shape and ready for attachment thereto of the desired end plates.

The particular object of the present invention is to provide a method and apparatus for making such cores in a continuous process beginning with a single strip or web of the basic structural material, such as kraft paper (as, for example, a roll of such material), and obtaining as an end product, a complete honeycomb core. The present invention envisages the inipregnating of the paper, or other material, the

14 Claims. (Cl. 154--1.8)

application of adhesive thereto, the heat-treating of the core, and thefinal setting thereof in ultimate form,so thatthe end product is ready to be cut into desired sections and used in the building of sandwich-type structures.

Thus, the novel continuous method of produc.- ing such fillers or cores, in accordance with the invention herein disclosed and claimed, converts, in a-steady flow of production, the original web of basic material into a finished core, 0 which, if desired, the end plates can be attached while the core emerges from the production line. In the utilization of the'ncvel apparatus, there are no interruptions for manual handling of the material between the difierent manufacturing steps, and therefore the present excessive labor costs are greatly reduced and an end product of greater uniformity is secured with a minimum of waste, material, time, and labor.

In the illustrated embodiment of the present invention, the apparatus comprises means, preferably cooperating rollers, suitably driven for advancing a strip or Web of the basic structure material, such as kraft paper, into a bath or the like of a suitableimpregnat-ing material The impregnatingmaterial, as the web is further ad-. vanced, may be dried but not cured by passage of the Web through a zone heated to a suitable temperature. The advancing means carries the dry impregnated web between cooperating roll: e'rs which form an aligned row of equally spaced perforations adjacent each marginal edge of the advancing web.

These rollers also, in the now preferred form of the apparatus, form on opposite faces of the web longitudinally extending pairs of scores with the pairs of scores on one face of the web laterally spaced in staggered relationship to the pairs of scores on the opposite face of the web. These scores form lines of weakness which facilitate subsequent bending or folding of the web along such lines in the actual. folding operation forming the cellular core structure. The apparatus also includes means for forming the web with'alternate rows of'slots, the slots of one row being staggered with respect to those of ad.- jacent rows. The mechanism forming the slots inthe advancing web. places these slots so that the slots of every other row are separated by the space between pairs of scores on one face of the web and the slots of the other rows are separated by the space between pairs of scores on the other face of the web.

Afterthe-web has been formed with the lines of slots, the advancing means carries-the web through mechanisms which apply to opposite faces of the advancing web longitudinally extending stripes of an adhesive material substantially equal in length to the distance between alternate rows of slots. The stripes are of a Width equal to the distance between pairs of adjacent lines of score with the stripes on the one face of the web laterally spaced in staggeredrelationship to the stripes on the opposite face of the web. The web is now pleated or folded alternately in opposite directions on the lines of slots to stack the folds contiguously to unite the same on said stripes of adhesive material as the folded web is continuously advanced to form the web into a fan-folded article. By suitable heating elements as, for example, high frequency inductors, the adhesive is set to secure a bond between the adhering portions of the pleats or folds while maintaining the pleats or folds under compression. The folded pack is thereafter expanded to form a honeycomb-like structure or pack, the lines of weakness formed by the scores facilitating bending or folding of the unsecured portion of the web to form the core with very regular shaped individual cells.

If the impregnant is fully cured prior to the expanding operation, the folded pack may be softened by steam to permit the folded pack to be expanded into the honeycomb-like structure. When the impregnant has not been fully cured. but merely dried, it is preferred to cure the impregnant by passing the same through 'a'curing oven or the like during the initial steps of expanding the folded pack so that the expanded stock will maintain the desired relationship of the cells of the honeycomb-like structure at the completion of the expanding operation.

The drawing illustrates a specific embodiment of apparatus in accordance with the invention:

Figures 1 to 4, inclusive, each on a separate sheet, together provide a diagrammatic flow sheet of the method and apparatus of the present invention. For purposes of orientation a baseor floor-line is indicated in each figure. At the righthand side of Figure l is a dotted line 2-2 I corresponding to a dotted line 2-2 at the lefthand side of Figure 2; and, accordingly, the lines 33 of Figures 2 and 3, and the lines -4 of Figures 3 and 4 correspond. Thus the four figures may be matched to provide a continuous diagram.

Figures 1A, 1B. 1C, 1D, 2A, 2B, 2C, 2D, 2E, 2F, 3A and 4A are details illustrating the condition of the stock from which the core is made at various stages of the production process. These figures are more particularly described below.

Figure IE is an elevational view of the cooperating rollers which perforate each marginal edge of the advancing web and form the longitudinally extending pairs of scores on the web.

Figure 2G is. an elevational view of one mechanism for applying to a face of the web longitudinally extending stripes of the adhesive material.

Figure 5 is the vertical section 55 of Figure 3.

Figure 6 is an elevational view of one of the upper blades carried by the apparatus illustrated in Figure 5.

The method of the present invention as illustrated in the drawing involves the following operations which are first briefly described in the order in which the same take place. In the drawing arrows indicate the directions of motion.

The stock from which the core is to be made. and which may be kraft paper, fabric, or other suitable material, is fed into the train of apparatus of the present invention, from, preferably, a mill roll such as indicated at i in Figure 1.

The stock in web form is first carried over an aligning roller 2 down into a tank 3 containing an impregnant with which the stock is to be treated. Such impregnant might well be an aqueous solution of phenolic plastic. In Figure 1 the web is shown to be carried down beneath two submerged rollers t and 5. After the web emerges from the bath, excess liquid impregnant is squeezed ofi by means-of presser rollers E; and l, the excess inipregnant draining back into the tank 3.

The stock is next carried through a suitable oven 8 having infrared lamps 9 therein for the purpose of partially drying but not curing the impregnant. If desired, other types of heating means could be employed for drying the impregnant.

The stock or web is then carried between two cooperating rollers id and H, as shown in Figures 1 and 1E, the former being provided with punches ma set at either end thereof at regu-- lar angular intervals, and arranged to cooperate with registered sockets i la in roller I i so that the opposite marginal edges of the stock are each per forated with a row of equally spaced aligned holes a (cf. Figure 1C). These holes may be relied upon subsequently in the apparatus train fitted with rollers or other advancing means hav ing pins engageable in the holes to insure travel of the stock through certain parts thereof at a predetermined rate of speed and to prevent slipping and misregister of the stock at various stages of the fabrication process. Rollers It and H may be" provided with spaced circumferential scoring ridges lfic so that the stock may be scored on both sides with longitudinal scores as it passes through these rollers.

Figure 1A shows a fragment of the stock in plan before it has entered between rollers l 0 and ii; Figure 1B is the section B-B of Figure 1A, Figure 10 shows a fragment of the stock in plan after it has passed between rollers ii) and H; Figure 1D is the section D-D of Figure 1C. Figures 10 and 1D show the relative spacements of the holes a and the longitudinal scores.

The scores are equally spaced, and each alternate pair of scores is made upon a different surface of the stock (of. Figure 1D, a sectional view). The scores upon the upper, i. e., near, surface of the stock or web, as shown in solid lines in Figure 1C, are designated b; those on the under side, as shown in dotted lines in the same figure. are designated 0. See also Figures 23 and 2F, the

' first being a plan view of a fragment of the stock seen from the upper side, and the second being a plan view from beneath.

Thus each surface of the web or stock is scored so that two intervals of spacement appear, one being equal to the basic score interval, and the other three times as great. See Figure 1C. The scores divide the two surfaces into parallel bands. The narrow bands of the upper surface are designated x, the wide bands Y, and the marginal bands of this surface a. The narrow bands of the under surface are designated 13, the wide bands c. and the marginal bands in (see Figure 2F). The purpose of scoring th stock, as will be understood, is to form lines of weakness which facilitate a subsequent bending thereof along such lines in forming the cellular core structure. In Figures 1C and 1!) it is readily seen that a nar row band on one surface of the stock or web is centrally disposed with respect to a wide band on the other surface, and vice versa. In other emopce :5 words,:the pairs ofscores on one ifaJCE-iOf. the web tor-stock are ;laterally.g;spaced in staggered ..-rela tionship with the pairs of scores on the :opposite face'of theweb.

Hie stock is next carried into apparatus at i2,

more zparticularly described below, which slots ;the..-s-tock transversely while th same is in :mo- .tion, :to provide the stock with alternate .rows of .slots (Zr-and e,, itheslots .ofone .row being staggered with respect to those of adjacent rows, as shown in FigureIZA. The length of any slot, except that .of .a marginal slot, is equal substantially to thrice the basic score interval. Slots dare centered withrrespect -to wide bands 11 of the under surface ofthe stock or web; slots 1:; are centered with :repectto wide bands y'of the upper 'surfaceoi the stock'or-web.

Atter the stock or web 'is :slotted it is carried tor-ward by means of friction vbelts i3 and i4,

whichare respectively mounted on pulleys iii-and t6 :andpulleys :l! and it. Although not shown, these friction belts are driven preferably at the same-rate of speed .as therate of forward move- .mentof themechanism .l 2.

Next the stock is carried between .a coating roller l9 and a pressure roller 2B, wherethe upper surfaceof the-stock :is-striped .intermittently with a .thermo-setting adhesive .along bands 50. See Figure 2E,..in which the intermittent adhesive striping. is designated f. In Figure 2E, the adhesive striping ,f is vindicated by vhachure whichhfor convenience extends from score to score and .from .slot to .slot, but, .in practice it is desirable that the striping be intermittent so that adhesive is not impressed upon the stock sufiic'iently close to the edge of a slot to leak thereinto and through to thelreverse surface. 'In Figure 3A,'a.figure showing part of the stock on a .much enlarged scale, the adhesive .striping j is indicated by dotted outline, audit is seen that the. edges of the intermittent striping do not coincide with the scores b and slots d.

In the now preferred form of the inventionthe intermittent striping j is applied'to the advancing web by means of interrupted circumferential lands i911, formed about the coating roller l9. This arrangement'of the lands is clearly shown in Figure '2G. Roller :19 is fed in'the manner known to the art with adhesive from a well '21 by means of a dipping'roller '22 and two transfer rollers' 23 and 24. Roller i9 is preferably given a slight axial reciprocating mo-tion'to insure good spreading of the-adhesive.

To insure proper-registry of the slotted web as it moves between the rollers I9 and '20, roller I9 is formed with a plurality ofpunches i 9b at each "end th'ereof at regular angular intervals and arranged to cooperate with registered sockets Eda formed in roller 28. The punches and sockets coact with the perforations a to move the 'web in proper registration between the rollers;

It should be understood that th punches and -rsockets are so formed relative to the lands idea to insure that the edges of the intermittent stripings I do not coincide with the scores :1) and 810135-11;v

After the upper :surface :of thestock has been coated-with :th adhesive the stock is reversed, as shown in Figure 2, by being carried over and around rollers 25, 525, '21, and'zliv Preferably the latter three-"of these rollers are provided with circumferential lands divided by grooves so that the .rollers contact the stock only 'at areas where the adhesive not present. :.;The stock, now reversedispassed between another adhesive :ap-,-

plyingsrollerszariand a pressure roll .3fl;sthis.f=lat.- 4

'6 ter preferably provided with: circumierentiakl grooves which permitigpassage 'of the stock zzwithout smearing therpreviously applied adhesive. Roll 29, having interrupted icircumferentiail lands, similar to the lands l-9a=of roller 49, 01),- erates to stripe, intermittently the other surface of the stock or web with adhesive along bands :f. Rollers 29 and .30, lik rollers .l9 and im-are formed with the coacting punches-:and-sockets to insure proper registration of the. :web :as it is advanced between these rollers. This arrange- .ment again is used to make sure that the stripe ings 7 are applied properly to the advancing web and to prevent the adhesive entering the scores band slots d. Figure 2? shows the lower surface of the stock in plan :after both sides hav been striped with .adhesive. The dotted haohure indicates, here, the previous striping .on the bandsim. In Figure 2F the intermittentadhesivestripes on bands 15 are designated g. The roller. .29 as .seen in Figure 2 is supplied with adhesive fromia-well 3| by means of adipping roller-'32 and two transfer rollers 33 and -34.

Thereafter the stock is again reversed, only-for the purpose 0f continuing the same in the .original direction of travel, by means of rollers .35 and 36, and is passed over roller .31, which :are preferably grooved circumferentially .to iavioidithe adhesive stripings, and between .a set of multiple feed belts 38 and 39,. respectively mounted: on pulleys til and M and pulleys A2 .and 43. It will be understood that now, as the stock or web has adhesive on .bothsides thereof, it. is desirable that the feed belts do not contact the imprinted surfaces.v Thus the feed mechanism preferably comprises a plurality of parallel A! belts, each having an exposed surf-ace of width .slightly less than thrice the. basic score interval, the belts 38 being staggered with respect to belts 39 so that the former contact the upper :surface of the :stock or web with the bands y andthe latter contact the lower surface .of the vstock within the bands .12, neither set :of belts thereby contacting the interrupted adhesive stripings, 1

Subsequently the stock ispassed through apparatus designated in its entirety 44,:and more particularly described below, which-operates:- to bend or fold the web transversely in different directions at the alternate rows of slots ,.as shown in Figure 3 .(see, also, Figure -3A,whi'ch shows a portion of the stock inperspective and illustrates the steps of forming the stock :into pleats -zor folds.

As will beseen, the opposed members per-orm .ing the :folding are synchronized in relationto each other and to the rate of movement of web such .aimannen .as to invariably fold the advancing web alternately in :opposite directions transversely "of -the Web at the tines of islets-to continuously produce a fan-folded pack "while the web is advancing. The web is so fan f-olded, referring now to Figure 3A; that the firstfdlding operation brings together the unincise'd: adhesive stripes on the one face of the "first two fold portions andthe second folding brings to gether the unincised adhesive stripes on the opposi-te faces of the next two fold portionsand :so on alternately, to the end that the finished pack :canbe expanded 'W-ithout rupturing any portion of the web.

Beyond the apparatus M the pleated stock or web is received between two additional :feed- #belts '45 :and 46, .respectively mounted on pulleys t"! and 48 and v pulleys 49 and 50 which belts are spaced them each" other by .a tilistanme -substantiall-y equal to the height of the desired core, 1. e., a distance substantially equal to the interval between the rows of slots d and e. Belts 45 and 46, driven of course at the same rate of speed, have a common velocity sufliciently less than that of the stock during its previous travel through the train of apparatus to cause the pleated stock to bank, as shown in Figure 3, so that each intermittent adhesive stripe f and g is forced against itself between the pleats of the stock and is so bonded. The web or stock, with its various pleats banked, and, in part, adhering each to the other, is next carried through an oven i wherein suitable heating elements, as, for example, high frequency inductors 52, heat the stock, dry the adhesive, and make the bond between the adhering portions of the pleats permanent, while the stock is fully compressed in pleated form between belts t5 and 45 and another set of belts 53 and 5d respectively mounted on pulleys 55 and and pulleys 57 and 58. In order to keep the pleats of the stock banked under compression while the latter is passing through the oven 5! the velocity of the belts 53 and 54 is somewhat less than that of the belts 45 and 46.

Beyond belts 53 and fa l the web or stock passes into an oven 59 having hot air or steam ducts 6i] feeding thereinto and a chimney SI wherein the impregnant may be cured, if the same has not been fully cured in the oven 55, or wherein, if the impregnant is fully cured, the stock itself may be softened (by steam) to prevent its tearing subsequently when the pleats are expanded 'to' form a honeycomb-like structure. Beyond the oven 59 the web is engaged by another pair of feed belts 62 and 33 respectively mounted on pulleys as and 55 and pulleys 8E and iii. The speed of belts 62 and E3 is sufficiently in excess of that of the belts 53 and 54 to sheet an expansion of the stock or Web between the two pairs of belts. Thus the banked pleats of the 'web are subjected to moments tending to open said pleats, but the adhering inner surfaces of the pleats cause the pleats to open only at the H nonadhering portions thereof, thereby forming a honeycomb-like structure, as indicated in Figure 4A. It will be understood, of course, that the length of the train of apparatus is not intended to be indicated by the drawing, and that suitable intervals between the individual apparatus are assumed to exist. These intervals, of course, relate back to the character of the adhesive and impregnant employed, the amount of heat required at the various stages, and the speed of operation. i

It is, of course, desirable that all stretching and distorting of the web or stock be at an end when the impregnant is completely cured to avoid fracturing the stock itself. It is sufiicient for the purposes of the present invention that the apparatus illustrated in Figure 4 is so arranged that the Web or stock'passes into the oven 59 in a fairly expanded condition and leaves said oven with the impregnant fully cured. The apparatus designated in its entirety as l2, Figure 2, is essentially a male die 160 and a cooperating female die It'll, each of which is carried on a pair of four parallel crankshafts, as indicated. Once such revolution of the shafts, which are synchronized, the dies clamp the stock between them while the latter is in motion, and the maleelements 202 (punches) of die Hill pierce -the stock and enter sockets I03 of die illl. Modifications will be apparent. There is here'shown an extremely elementary arrangement of apparatus for slotting the stock while the same is in motion.

The apparatus designated in its entirety 44, Figure 3, comprises a plate member Hll having two blades HI and H2 rigidly fixed thereto, and another plate member H3 having an oppositely disposed blade H4 rigidly fixed thereto and centrally disposed with respect to the first mentioned blades. Both plates are mounted on crank shafts, and the shafts rotate synchronously. Once each revolution the blades assume the position indicated in Figure 3, and bend the web or stock in alternate directions at each alternate row of slots. Figure 6 shows blade H2 by itself in elevation; Figure 5 is the elevational and sectional view indicated by line 5-5 of Figure 3. It will be noticed in Figure 6 that the edge of the blade H2 is stepped back at intervals so that the edge will not contact the several segments of the interrupted adhesive stripes when bending the stock. Blades Ill and H4 are similarly formed, except that, of course, blade H4 has step-backs staggered with relationship to those of blades HI and H2.

There is claimed:

1. Apparatus for the continuous production of a honeycomb core for sandwich-type structures from a single web of material being fed continuously which comprises a male and a female die periodically cooperating and slotting said web with a series of parallel transverse rows of slots, the slots of any row being staggered with respect to the slots of adjacent rows; means for applying on both sides of said web longitudinally extending intermittent stripes of adhesive between the slots of every other row on one side of said sheet and between the slots of the other rows on the other side of said web; cooperating, reciprocating blades continuously pleating the advanced portion of said web by bending it in alternate directions at each alternate row of slots; cooperating feed belts engaging the arrises of the pleats so formed, said belts traveling at a rate of speed less than that of the feed of said web and thereby backing up said pleats upon one another; other cooperating feed belts engaging the arrises of said pleats, the second named belts traveling at a rate of speed less than that of the first named belts and thereby compressing said pleats and bonding within each pleat one portion of each of the stripes of adhesive to another portion thereof; and other cooperating feed belts engaging said arrises, the third named belts traveling at a rate of speed in excess of that of the second named belts, thereby separating the unbonded portions of said pleats and expanding said pleats into a honeycomb-like structure.

2. Apparatus of claim 1, including means for forming a row of aligned apertures adjacent each marginal edge of said web, and advancing means carrying pins for reception in said apertures for thereafter advancing said web.

3. Apparatus of claim 1, including means "for impregnating the material of said web prior to slotting, with a thermo-setting reinforcing agent, said means comprising a bath of such agent and guide rollers routing the web through such bath.-

4. Apparatus of claim 1, including means for impregnating the material of said web, priorto slotting, with a thermo-setting reinforcing agent,

said means comprising a bath of such agent and guide rollers routing the web through suchbath'; and means for dryingsaid agent after. .the same spe -nee ing and slotting said web with a series of parallel transverse:rows ofslots,-the-slots of any row being --staggered with respect to the slots of adjacent rows, and the slots of every otherrow being-separated by the space between pairs of scores on one side of said'web and the slots of "the other I rows being separated by the space between pairs of scores on the other side of said web; coating surfaces for applying on both sides'o'i said web longitudinal stripes of adhesive between "each "pair of scores thereon; cooperating, reciprocating blades continuously pleating the advancing web "by bending it in alternate directions at each alternate row of slots; "cooperating feed belts engaging the --arrises of the pleats so formed, said belts traveling at a rate of speed 'less than that ofthe feed of said web and thereby backing up said'pleats upon one another; other cooperating feed "belts engaging -the-arrises of said pleatsgthe second named belts traveling. at a rate'o'f speed less than the first namedand thereby compress- 1 'ing said pleats and bonding within each pleat one "portion or each of the stripes of adhesive'to another portion thereof; and -other cooperating "feed belts engaging said arrises the third "named belts traveling at a rate-of speed in excess o'f that oi the second named belts, therebyseparatingthe unbonded portions ofsaid pleats-and expanding said pleats into a honeycomb-like structure.

6. Apparatus for the continuous production "of a honeycomb core iro1n-a continuous web of =material, comprising: means at the input end of the aparatus for supporting a supply ofthe web material; means forcontinuously advancing the web therefrom; means for impregnating said-advancing web with a thermo-setting reinforcing agenty means for -drying said agent; means for longitudinally scoring said "advancing web on both 'faces thereof with a-series of scores in pairs,

the pairs of scores on one face being located midway between the pairs of scores on the other ia-co; means for inc'ising the advancing web "in transversely extended longitudinally equidistant lines of slots, the slots of any row being staggered with respect to-the s'lots'of adj-acent rows, and the slots ofeveryother row being separated'by the pace between pairs ofscores on one vface -of .said web and :the slots of theother rows'being separated bythezspace between pairs of scoreson theaotherface of said web; 'imeans :5for appl'ying 'to opposite races of the advancing WBb longi- :tudi-nally extending ;.stripes of uniting :material with the lines on t-h'e one .facerelatively spaced :in staggered relationship to .the z-stripes on the other face, said stripes of :uniting material :hav-

zinga'width substantially equalto the distance. between each pair of scores; 'cooperating, nieciprocating :blades continuously pleating the ad- :vancing web by bending it .inalternatedirections :at each alternate :row -;-of slots; :cooperatingieed zbeltssengagmgthe'arrisescof the'pleatsszso iormed,

, :oadvancinaweb longitudinally zaextendingilines :bf

' of the contiguous pleats; and other cooperating ieed belt-s engaging said-ar-rises,-the third named belts traveling at a rate of speed in excess of that of the second named belts thereby separatmg the 'un-bonded portion of said pleats along said scores and expanding said pleats into a honeycomb structure.

'1. Apparatus for the continuous production-of a honeycomb core from a'continuous Web of ma- *terial, comprising: means at :the input end ofthe apparatus for supporting a supply of the web :material; means for continuously advancing the web therefrom; means for longitudinally scoring saidadvancing web ch -both surfaces-thereof with a-series-of scores :in pairs, the pairsof scores on one iace being located midway betwen the pairs of scores on the other face; means for incising 'theadvaneing web in' transversely extending lon- 'gitudina'lly -equidistant rows of slots, the slots of any-row being staggered with respect to the-slots of adjacent rows, and the slots :of every other row being separated by the-space between :pairs of scores on one face of :said web and :the slots of "the other rows being separated "by the space between pairs of scores on-the other tfiace of said web; means for applying -to opposite 'faces'of the advancing-Web longitudinally extending lines 01: uniting material-with the lines on the one face relatively spaced in staggered relationshipto the lines on the other face, said linesof uniting material having a Widthsubstantially-equal to the distance between each pair of scores; means for folding the advancing web alternately .in opposite directions on said longitudinally equidistant transversely extending rows of slots; -meansfor stacking the folds -=contiguously to unite the same on said' lines of uniting material to iorm a-depthwise, breadthwise; multi-cellu'lar, longitudinally relatively compact mass of -a depth equal to-the distance between said rows of slots; means, *ineluding means engaging the 'arrises of the folded said' advancing webion both-surfacesathereof with anyrowwbeing staggeredwith respectztowthaslots of adjacent rows, and the :-2S10ts of .eevery :other zrow being-separated by :the space between :pairs .of scores :on onerface ;of said web :and 'thBcSlDtSzDf Lthe otherrows sbeingseparated :by :the space lee-- rtweenz pairs .of :scores 5011 the other face 501?; said aveb; :meanssfor applying :to opposite 'racescof tthe unitingwmatwial with rtheilines onrthe one.vv face 11 relatively spaced in staggered relationship to the lines on the other face, said lines of uniting material having a width substantially equal to the distance between each pair of scores; cooperating, reciprocating blades continuously pleating the advancing web by bending it in alternate directions at each alternate row of slits; cooperating feed belts engaging the rises of the pleats so formed, said belts traveling at a rate of speed less than that of the speed of said web and thereby backing up said pleats upon one another; other cooperating feed belts engaging the rises of said pleats, the second named belts traveling at a rate of speed less than the first named pair of belts and thereby compressing said pleats and bonding within each pleat one portion of each of the lines of uniting material to another portion thereof to effect mutual facewise contact of the contiguous pleats; and other cooperating feed belts engaging said rises, the third named belts traveling at a rate of speed in excess of that of the second named belts thereby separating the unbonded portion of said pleats and expanding said pleats into a honeycomb structure.

9. An apparatus for making from an elongate web a depthwise foraminous reticule comprising: means for advancing the elongate web into the zone of operations; means for impregnating the Web with a thermo-setting reinforcing agent; means for drying said agent; means for incising the advancing web on transversely extending longitudinally equidistant segmental lines of slots; means for applying to opposite faces of the advancing web longitudinally extending lines of layer uniteable material with the lines on one face of the web laterally spaced in staggered relationship to the lines on the other face; means for folding the web alternately in opposite direction along said lines of slots; means for stacking the folds contiguously to unite the same on said lines of uniteable material as said folded web is continuously advanced to form a lengthwise compact depthwise and breadthwise multicellular mass of a thickness equal to the distance between said lines of slots; means for heating said mass means for moving said mass into heating relationship with said heating means to set said reinforcing agent; and means for thereafter expanding said advancing mass to form a honeycomb-like foraminous reticule, said last named means including means for applying steam to said expanding mass to facilitate expansion of said mass.

10. Apparatus for manufacturing a honeycomb core from an elongate web, comprising: means at the input end of the apparatus for supporting a supply of the web material; means for advancing the web therefrom forwardly of the apparatus; means for impregnating said web with a thermo-setting reinforcing agent; means for drying said agent; cooperating means for incising the advancing web in transversely extending longitudinally equidistant lines of slots; means disposed adjacent opposite faces of the advancing web for applying to said opposite faces longitudinally extending lines of uniting material with the lines of uniting material on the one face laterally offset in staggered relationship to the lines of uniting material on the opposite face; means for folding the advancing web alternately in opposite directions on said longitudinally equidistant transversely extending lines of slots; means for stacking the folds contiguously to unite the same on said lines of uniting material as said folded web is continuously advanced to form a depthwise, breadthwise, multi-cellular, longitudinally relatively compact mass of a depth equal to the distance between said lines of slots; means for applying heat to said advancing mass to set said reinforcing agent; and means, including means for bathing said mass in steam to soften the same, for thereafter expanding said advancing mass to separate the folds thereof to form a honeycomb core. I

, 11. An apparatus for making a honeycomb core from a web, comprising: means for advancing the web into the zone of operations; means for forming on opposite faces of the advancing web a series of longitudinally extending lines of weakness in pairs, each adjacent pair of lines on one face of said web being laterally spaced in staggered relationship to adjacent pairs of lines on the opposite face; means for forming transversely extending rows of slots in the advancing web at longitudinal equidistant stations thereof, with the slots in adjacent rows so mutually staggered laterally that the slots in one of said adjacent rows are intersected by adjacent pairs of lines of weakness on one face of said web and the slots in the other of said adjacent rows are intersected by the adjacent pairs of lines of weakness on the other face of said web so that the slots of every other row are separated by the space between pairs of lines of weakness on one face of said web and the slots of the other rows are separated by the space between pairs of lines of weakness on the other face of said web; means for applying to opposite faces of the advancing web longitudinally extending stripes of adhesive material with the stripes on the one face laterally spaced in staggered relationship to the stripes on the opposite face; means for folding the advancing web alternately in opposite directions on said lines of slots; means for stacking the folds contiguously to unite the same on said lines of adhesive material as said folded Web is continuously advanced to form the web into a fanfolded article; and means for thereafter expanding said fan-folded article to form a honeycomb having a multiplicity of cells defined in part by said lines of weakness.

12. Apparatus for the continuous production of a honeycomb core from a continuous web of material, comprising: means at the input end of the apparatus for supporting a supply of the web material; means for continuously advancing the web therefrom; means for impregnating said advancing web with a thermo-setting reinforcing agent; means for drying said agent; means for longitudinally scoring said advancing web on both surfaces thereof with a series of scores in pairs, the pairs of scores on one face being located midway between the pairs of scores on the other face; means for incising the advancing web in transversely extended longitudinally equidistant lines of slots, the slots of any row being staggered with respect to the slots of adjacent rows, and the slots of every other row being separated by the space between pairs of scores on one face of said web and the slots of the other rows being separated by the space between pairs of scores on the other face of said web; means for applying to opposite faces of the advancing web longitudinally extending stripes of uniting material with the stripe on the one face relatively spaced in staggered relationship to the stripes on the other face, said stripes of uniting material having a width substantially equal to the distance between each pair of scores; means for continuously pleating the advancing web by bending it in alternate directions at each alternate row of slots; means for stacking said pleats upon one another and thereby compressing said pleats to unite the same on said stripes of uniting material; and means for separating the unbonded portion of said pleats along said scores and expanding said pleats into a honeycomb structure, said last named means including means for heating said reinforcing agent to set the same.

13. Apparatus for the continuous production of a honeycomb core from a continuous web of material, comprising: means at the input end of the apparatus for supporting a supply of the web material; means for continuously advancing the web therefrom; means for longitudinally scoring said advancing Web on both faces thereof with a series of scores in pairs, the pairs of scores on one face being located midway between the pairs of scores on the other face; means for incising the advancing web in transversely extending 1ongitudinally equidistant rows of slots, the slots of any row being staggered with respect to the slots of adjacent rows, and the slots of every other row being separated by the space between pairs of scores on one face of said web and the slots of the other rows being separated by the space between pairs of scores on the other face of said web; means for applying to opposite faces of the advancing web longitudinally extending lines of uniting material between each pair of scores thereon; means for folding the advancing web alternately in opposite direction on said longitudinally equidistant transversely extending rows of slots; means for stacking the folds contiguous- 1y to unite the same on said lines of uniting material to form a depthwise, breadthwise, multicellular, longitudinally relatively compact mass of a depth equal to the distance between said rows of slots; and means for separating the unbonded portion of said folds and expanding said mass into a honeycomb structure having a multiplicity of cells defined in part by the lines of score.

14. Apparatus for manufacturing from an elongate Web a depthwise foraminous reticule, comprising: means at the input end of the apparatus for supporting a supply of the web material; means fOr advancing the web therefrom for wardly of the apparatus; means disposed adjacent opposite faces of th advancing web for longitudinally scoring both faces of said advancing web with a series of scores in pairs, the pairs of scores on one face being located intermediate the pair of scores on the other face; cooperating means for incising the advancing web in transversely extending longitudinally equidistant lines; means disposed adjacent opposite faces of the advancing web for applying to said opposite faces longitudinally extending lines of adhesive material between each pair of scores thereon; means for folding the advancing web alternately in opposite directions on said longitudinally equidistant, transversely extending lines of incisions; means for stacking the folds contiguously to unite the same on said lines of adhesive material to form a depthwise, breadthwise multi-cellular,

longitudinally, relatively compact mass of a depth equal to the distance between said lines of incisions; and mean disposed onwardly of said folding means for separating the unbonded portions of said folds and expanding said mass into a honeycomb structure having a multiplicity of cells defined in part by the series of scores formed on the opposite faces of said web.

IRMA UNGAR, Administratrz'x of the Estate of Gustave A. Ungar,

deceased.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,473,096 Hill et a1 Nov. 6, 1923 2,333,024 Mathes Oct. 26, 1943 2,472,863 Socke June 14, 949 2,581,421 Lombard et al Jan. 8, 1952 

